A wireless local area network (WLAN) is a network in which communication is performed by means of wireless media. The WLAN is a combination of a computer network and communications technologies, and generally includes devices such as an access point (AP) and a station (STA). The STA is also referred to as a terminal or an access device.
The access point may be connected to a wireless network, or may be connected to a wired network. The access point may also be referred to as a hotspot. A hotspot covered by a wireless local area network used at home is referred to as a home hotspot. The home hotspot (including a client device having a wireless fidelity (WiFi) AP function) performs uplink transmission by using the Ethernet, and is fixedly disposed at home as an ingress of the Internet. Therefore, the home hotspot is not portable. A mobile hotspot, for example, mobile WiFi, is mainly used to provide outdoor wireless local area network coverage. The mobile hotspot is portable and can perform high-speed data services by using the 4th-generation mobile telecommunications technology (4G)/3rd-generation mobile telecommunications technology (3G)/2nd-generation wireless telephone technology (2G).
A growing quantity of user terminals can access the Internet by using the foregoing two access points, so as to implement services such as web browsing, data transmission, or a voice call. Generally, if a terminal is outside a coverage area of a wireless local area network at home, the terminal can access the Internet by using a mobile hotspot. When the terminal is within the coverage area of the wireless local area network at home, the terminal can access the Internet by using a home hotspot. However, when the terminal device moves into the coverage area of the wireless local area network at home from outside of the coverage area of the wireless local area network at home, the terminal is still connected to the mobile hotspot outside the coverage area of the wireless local area network at home and cannot automatically switch to the home hotspot. To implement the switching, a user has to manually disable the mobile hotspot and connect to the home hotspot, or has to manually scan for other hotspots on the terminal and then disconnect the terminal from the mobile hotspot and connect to the home hotspot. It can be learned that, a terminal cannot perform automatic switching within a coverage area of a wireless local area network at home by using the foregoing technology.